STRIDE - STimulating Immune Response In aDvanced brEast Cancer

Inclusion Criteria: * Postmenopausal women as defined in the protocol * Estrogen receptor (ER)-positive and/or progesterone receptor (PgR)-positive, histologically or cytologically confirmed primary carcinoma of the breast * Expressing at least one of the following five human leukocyte antigen (HLA) haplotypes, as centrally assessed by HLA genotyping from whole blood: HLA-A2, -A3, -A11, -B7, or -B35 * Locally advanced, recurrent, or metastatic breast cancer (Subject must have at least one lesion not located in bone) * Measurable disease by Response Evaluation Criteria in Solid Tumors (RECIST), and inoperable * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 * Adequate hematologic, hepatic, and renal function within two weeks prior to initiation of therapy, as defined by the protocol * Other protocol-defined inclusion criteria may apply Exclusion Criteria: Disease Status * PD either during hormonal therapy for early breast cancer (adjuvant therapy) or within 48 months from the initiation of such therapy * Human epidermal growth factor receptor 2-positive (HER2+) breast cancer as defined in the protocol * Autoimmune disease that in the opinion of the investigator could compromise the safety of the subject in this study (Exception will be granted for well-controlled Type I diabetes mellitus) * Recognized immunodeficiency disease, including cellular immunodeficiencies, hypogammaglobulinemia or dysgammaglobulinemia; hereditary or congenital immunodeficie…